


our intention creates our reality

by Seito



Category: Final Fantasy XV, Katekyou Hitman Reborn!
Genre: Alternate Universe - Canon Divergence, BAMF!Tsuna, Crossover, Fluff, Fuck the Prophecy, Isekai AU, M/M, Reveal, World of Ruin
Language: English
Status: Completed
Published: 2020-06-23
Updated: 2020-06-23
Packaged: 2021-03-04 00:26:51
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,659
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24874579
Author URL: https://archiveofourown.org/users/Seito/pseuds/Seito
Summary: Noctis left the Crystal ready to die to save the world. Convincing his boyfriend it was the only way was proving to be every bit as painful as he expected.(OrTsuna: I’m going to punch Ardyn.Noctis: *gasp* Tsuna, no!Tsuna: Tsuna YES! )
Relationships: Noctis Lucis Caelum/Sawada Tsunayoshi
Comments: 36
Kudos: 358
Collections: KHR Rare Pair Week 2020





	our intention creates our reality

**Author's Note:**

> for khrrarepairweek2020   
> Sun Day: Isekai AU | Shocking Reveals

“No.”

Noctis made a pained noise. “Tsuna,” he half begged. This… was not how he wanted to spend this reunion. But what choice did he have? 

Ten years trapped in the Crystal. Ten years of feeling all of Eos fall into darkness. Ten years of with Bahamut, with the weight of his ancestors’ arms, with the cursed truth of the prophecy. 

Noctis knew that his friends, his _brothers,_ would have been there for him when he was released for the Crystal. That much he knew. They could have walked away (he onced feared that Gladio would), but he knew soul-deep that they would be there. (Maybe that was just more prophecy, more fate, more threads that bind him to his role as Chosen King. Noctis wasn’t sure if he was bitter over the lack of choice to his brothers or too relieved to know that there would be a fragment of normality that would await him.) 

Tsuna… was a little bit harder. 

Noctis’ boyfriend of two years (or… technically twelve?) was a wild card. On one hand, while Tsuna bowed graciously to the fact that Noctis had been suddenly betrothed to Lunafreya due to the trap of a peace treaty, there was always… a certain… contradiction factor with Tsuna. 

Noctis used to love the little thrill, the certain oddity of dualism that Tsuna presented. He still did. (Still thought it was hot). But Tsuna had always been an odd conflict of too meek, too confident at the same time. Tsuna would freak out at the sight of dogs, but refuse to bow to bullies. Tsuna balked at the idea of talking to teachers, but looked Regis straight in the eye. Too soft. Too rigid. 

Navigating the waters to figure out what made Tsuna tick was what made their relationship half the fun it was. 

Too many people thought Noctis was too naive, too sheltered. Noctis had always been aware of the fact that he saw people and their potential far too clearly. It was always a double edge sword. Noctis could always read the intent that people had. That was why his friendship with Prompto blossomed so fast because he knew that Prompto genuinely wanted his friendship, no strings attached. People accused Ignis of being too stoic, too cold, too hard to read when Ignis was always an open book to Noctis, who burned a little too passionately that Noctis feared that Ignis would one day burn himself out. Gladio didn’t even realize that half of Noctis’ bratty behavior was because Noctis knew that Gladio didn’t know, wasn’t ready to handle the role of Shield, but knew the role of big brother very well. 

The only people who Noctis had trouble with were Ardyn and his father. His inability to read what Ardyn wanted was what set Noctis' instincts on high alert. He didn’t trust Ardyn, but had no choice but to rely on him.

The opposite came into play with his father. Noctis could read what Regis’ intent always was. It was always the same thing, unwavering even as the years passed. Everything his father did was out of love for Noctis. 

Noctis left Insomnia none the wiser because he father didn’t say anything, more concerned for Noctis’ safety, even though he knew it was a trap, that it was possibly the last time they saw each other and Noctis regret everything about that last moment, too busy playing the sullen young prince.

Even now, knowing that his father chose to hide the truth of Noctis’ role as Chosen King wasn’t met with anger. Just a bittersweet understanding that Regis was trying to protect him. 

Tsuna was very much like Regis. Noctis could always read Tsuna’s intent for the most part. He knew that Tsuna really did love him, still loves him. He could read Tsuna’s love very easily. But Tsuna didn’t always… follow through with his intent. 

Tsuna hated tuna yet always ordered maguro at the sushi restaurant Noctis worked part time at. Tsuna said cats were the best pet but always stared longingly at chameleons. Tsuna said he wasn’t a fan of the color orange, but owned at least half a wardrobe of that color. Tsuna who smiled and said he was fine when he really wasn’t. 

Noctis had never met a better liar. 

It was such a contradiction. 

Their first meeting involved Tsuna dodging every social interaction, never looking anyone in the eye, body posture screaming to be left alone except there was something about him that was begging for anyone to see him.

(Noctis wasn’t sure what caused him to reach out, but he never regretted it.)

(Was it too sappy to say that before all of this, before Insomnia fell, before his father’s death, before the truth of the prophecy, Noctis knew that he was going to marry Tsuna one day?) 

(Noctis regretted that it would never come true.)

(He carried so many regrets.) 

“Tsuna,” Noctis said again, softly, gently. “It’s the only way.” 

He had ten years to come to terms with this. Did he want to die? No. Never. There was still so much he wanted to do. 

(A wedding.)

(A smile.)

(A family.)

But Noctis was the King of Lucis. He was the Chosen King. He was the King of Kings. He had a duty. He could not be selfish.

Not here. Not. Now. 

No matter how much he wanted it. 

Noctis stared at Tsuna, soaking in his details. He missed ten years and Tsuna had gone from lanky to solid lean muscle. His hair was still a fluffy brown mess, but like Prompto, like Ignis, like Gladio, there was a weariness in his eyes. An exhaustion from living in this hard world of darkness. The sun would return with Noctis’ death, the Starscourge finally gone from this world. 

If Noctis could give them back to them, back to the whole world, then it was worth dying for. 

“No, it isn’t,” Tsuna said. His eyes flashed a brilliant bright orange for a single moment.. “You-, I just got you back,” he whispered. “You can’t leave again.” 

“Tsuna,” Noctis said, pained. “Please,” 

Any courage Noctis had summoned up from the ten years in Crystal would snap if Tsuna asked him to stay. 

(He wanted Tsuna to ask him to stay.)

(That wasn’t fair.)

(None of this was fair.)

(But what choice did Noctis have?)

“There must be another way,” Tsuna said. 

“There is none,” Noctis said. He had asked this multiple times. Part of him wondered if Bahamut had kept him for ten years because it wasn’t until the 10th year that Noctis had truly, finally, accepted this. “It was ordained by Bahamut himself. This is the only way to stop Ardyn, to stop Starscourge, to bring back the sun.” 

Tsuna _snarled_. 

“Tsuna?” Noctis said, wary. Tsuna rarely got angry but when he did, it was often a sign to run for cover. 

“Fuck Bahamut,” Tsuna said. Anger and tension was rolling off him like tidal waves. “If we get rid of Ardyn, we get rid of Starscourge, and the sun comes back right?” 

“Ardyn is effectively immortal,” Noctis said. 

“Semantics,” Tsuna said. “The only reason why you need to die is because Ardyn needs to die on a spiritual level as well as a physical level. I knew I should have punched him back in Altissia.” 

Noctis gaped. “Tsuna, no. You’re not punching Ardyn. He’s dangerous! You saw what he did to Ignis!” 

The only reason why Ignis walked away from Altissia blinded in only one eye was due to Tsuna’s timely intervention. Ardyn could have done so much more damage to Ignis and Noctis hated the fact that Ignis had even gotten hurt that badly in the first place. 

Tsuna gave him a fierce look. His eyes seemed to glow, a fire dancing them. “Noctis Lucis Caelum do you love me?” 

Noctis blinked. “Yes,” he said with no hesitation. 

“Do you know that I love you?” Tsuna asked. 

“Yes,” Noctis said. That hadn’t changed, even ten years later. It was still as clear as water to Noctis. 

“Then in case you didn’t figure it out ten years ago, I always protect those I love with my Dying Will.”

Noctis tilted his head, practically hearing the capitalization of those last two words. “Tsuna?”

Tsuna didn’t meet his eyes, staring at his hand as it flexed it open and closed. “I’m not a nice person, Noct.” 

“You’re a kind person,” Noctis said. There was a difference between nice and kind. Tsuna _chose_ kindness. 

Tsuna snorted. “Maybe. Maybe once upon that’s exactly the type of person I would have been. But no matter what, you don’t forget where you came from. Even if it’s a brand new world and everything has been reset.”

“I thought I was supposed to be the mystifying one in the relationship,” Noctis joked. 

“Do you remember my warning to you about if you ever run into a guy with spiky white hair, purple eyes and purple triangles under his left eye?” Tsuna asked. 

“Yeah stab him and run,” Noctis said. 

It was yet another contradiction about Tsuna. He hated violence and fighting, only learning as a means of self defence. But he also picked the most up close and personal method to fight with, his fists. 

“He’s the man who taught me how to be ruthless,” Tsuna said. “It was… something not even my tutor, the World’s Greatest Hitman managed to blossom in me. But him? He turned me into the one thing I fought against my whole childhood.” 

A chilled, haunted look reflected on Tsuna’s face. “There is no room for kindness in the mafia, Noct.”

Noctis furrowed his brow. He didn’t understand. When and why and how was Tsuna tied up with the mafia? Them dating meant extensive background checks, even spying, Tsuna’s background came back clean. Not to mention there wasn’t even that big of a mafia group in Insomnia back in the day. A few criminal rings, but Kingsglaive had been through enough that none, to Noctis’ knowledge, lasted more than a few years before they had been brought down. 

Outside of Insomnia? Sure. But Tsuna’s background check said he never left Insomnia. Even if that was a lie, it had to have happened when Tsuna was _very_ young because in the two years they were dating, there was barely a day that Noctis didn’t see his boyfriend. Same for the three years before that, when they first met and were attending school together with Prompto. It could have happened after school or the weekend, but… no, it was almost impossible. 

It could have happened in this ten year gap, except Tsuna’s warning about a spiky white haired man was spoken to him after a month of friendship. 

“Any means necessary, ruthless and cold as a bullet to the head, no mercy for any, blood for blood, forgiveness never to be given. That is what it means to be a mafia don. That is what it meant to be Vongola Decimo,” Tsuna said, smile growing tighter. “I promise myself that I would not dip into those skills, that mindset.” 

“Tsuna you don’t-” Noctis started. 

“You’re worth it,” Tsuna said fiercely, tenderly. “You’re worth it and you need to understand that I would burn down this entire planet for you, if you ask me.”

“I wouldn’t,” Noctis said. 

Tsuna grinned at him, full of teeth and leaking with bloodlust. “I know. That’s why I’m going to punch Ardyn.” 

-.-.-

“So, uh, what exactly is the plan?” Prompto asked. They stood outside of the throne room. Even with the thick, reinforced heavy doors in place, all of them could feel the taint of Starscourge coming from inside of the throne room. Ardyn awaited them inside. “The plan that does not involve Noct dying?”

“Tsuna is going to do something stupid,” Noctis said glumly. He recognized there was no stopping his boyfriend. 

“It’s not stupid. It’s saving your ass,” Tsuna said, crossing his arms. 

“You’re planning on punching Ardyn in the face,” Noctis argued. 

“I believe I had dibs on that,” Ignis said. 

“No, Iggy,” Gladio said with a tired sigh. 

“Too bad,” Tsuna said. 

“Okay, like I want to punch Ardyn too,” Prompto said. “But how exactly does that solve Noct not dying?” 

Tsuna tugged at his black metal cladded gloves. “There’s a story I grew up with,” he said. “It may seem silly and strange to you, but I promise it is true. Flames of the Sky, rainbow colored for each element. Storm burns a bright red, capable of disintegrating anything it touches. Sun is a shining yellow, activating oneself and others. Rain is a soft blue, spreading tranquility and calming even the wildest tsunami. Lightning strikes with an electric green, its quick and hardened frame capable of protection. Mist hid in soft indigo, constructing illusions that could fool the brain. Cloud a gentle purple, propagating far beyond the eye could see.” 

Tsuna smiled fondly. “Last but not least, the ruler of them all, Sky Flames. Sky is orange and sings harmony. Accept all without contradiction or flaw, the balance of the whole is maintained.”

Noctis blinked. That explained the orange in Tsuna’s wardrobe. A subsconscious draw to the color? “You have Sky Flames,” he said. 

Tsuna nodded. 

“That sounds really cool except I still don’t get how it really helps us,” Prompto said. 

“They’re called Dying Will Flames of the Sky,” Tsuna said. 

Noctis blanched. “Dying Will? We’re not doing a trade off. You’re not dying for me, Tsuna!” 

Tsuna laughed. “Now you know how I feel about you announcing that you would willingly walk to your death. But fear not. Dying Will Flames is a high density form of energy refined from one’s own life-force, but it does not actually kill me to use it.” 

“That’s still not a reassuring name,” Ignis said. 

“I didn’t name it,” Tsuna said with cheer. “But the most important thing to know is that Dying Will is a mindset, it is an intent. Even though it looks like fire, it will not burn if the user does not wish it to.” 

His eyes gleamed with a bright orange. Orange flames sparking to life around his hands and forehead. “It also means there is absolutely _**nothing**_ I cannot burn with my Dying Will.” 

The room exploded with a sea of orange fire. Before Noctis could even comment on it, it condensed. 

“XX BURNER!” 

Noctis gaped. The throne room was gone. Completely obliterated. “Holy shit, Tsuna.” 

“I told you, I would burn down this entire planet for you,” Tsuna said. He pressed a quick peck to Noctis’ lips. “Now sit your cute butt down. We are not done talking about why dying because of a prophecy is cosmically such a bad idea. But first, I’m going to make sure Ardyn stays down this time.” 

He took off, leaving behind a trail of orange flames. 

“Well, well,” Ignis said. “I can’t believe he has never shown that to me.” 

“Iggy, no,” Gladio said. 

“I’m so glad you’re marrying him,” Prompto said. “You are marrying him, right Noct?”

Noctis snapped his jaw shut. “Of course!”

“It’s a good thing I still have the ring Noctis picked out eleven years ago,” Ignis said. 

“Knew even back then, huh?” Gladio said. 

“Of course!” Noctis snapped, face burning a bright red. For Six’s sake, he was thirty years old and his best friends were making him feel like an awkward teenager at sixteen. 

Another pillar of orange flames surged to life. It rose like a beacon, high into the sky. Noctis stared in wonder as he watched it spread like a wildfire, consuming the Starscourge that blanketed the sky. 

Slowly, surely, a blue sky appeared, sun beams pouring down. 

He didn’t have to die. 

Noctis left loose a hysterical giggle. “I am going to spend the rest of my life making sure Tsuna is nothing but happy.” 

It was the least he could do. 

**Author's Note:**

> picture TYL!Tsuna who instead of being murdered got reborn into a new dimension thanks to Byakuran. TYL!Tsuna is very pissed off at that, but he did get to meet his very cute boyfriend, one Noctis Lucis Caelum so... there are upsides. (He misses his friends but there's no Vongola here. It's never been more freeing) 
> 
> (But you also don't forget the blood that stains your hands either.) 
> 
> (Or the skill set required to do that.) 
> 
> Please leave a review on your way out :D


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